[Home]   [Full version]  

NASA approves construction of satellite to scan galaxies

Oct 19 ,Space & Earth science


After eight years of study, NASA has approved the construction of an unmanned satellite that will scan the entire sky in infrared light to reveal nearby cool stars, planetary "construction zones" and the brightest galaxies in the universe. Launch of the Wide-field Infrared Survey Explorer (WISE) -- the second phase of the WISE mission -- is scheduled for late 2009. The satellite will orbit the Earth and operate for at least seven months, with data expected a few times a day.

Edward L. (Ned) Wright, UCLA professor of physics and astronomy, is WISE's principal investigator. NASA's Jet Propulsion Laboratory in Pasadena will manage the mission, with JPL's William Irace as project manager.

Like a powerful set of night-vision goggles, WISE will survey the cosmos with infrared detectors 500 times more sensitive than those used in previous survey missions.

"This mission has incredible power for discovery," Wright said. "I expect that what we find will be amazing. There is still so much we don't know."

Wright said that 99 percent of the sky has not been observed yet with this kind of sensitivity, and that the survey should be able to find and observe at least 100 million galaxies and hundreds of nearby cool stars that are currently unknown.

"Approximately two-thirds of nearby stars are too cool to be detected with visible light," Wright said. "WISE will see most of them."

He added that proto-planetary discs around stars presumably condensing into a planetary system show up in the infrared. "Several have been detected, and we will be able to see many more in the Milky Way galaxy," Wright said. "In addition, we will be able to study star-forming regions in nearby galaxies and star formation in distant galaxies."

Such extensive sky coverage means that the mission will find and catalogue all sorts of celestial eccentrics, including perhaps elusive brown dwarfs close to the Earth. Brown dwarfs, the missing link between gas giant planets like Jupiter and small, low-mass stars, are failed stars about the size of Jupiter, with a much larger mass. They can be detected best in the infrared, but even within the infrared are very difficult to detect.

"Brown dwarfs are lurking all around us," said Peter Eisenhardt, project scientist for WISE and JPL. "We believe there are more brown dwarfs than stars in the universe, but we haven't found them because they are faint."

Galaxies in the distant, or early, universe were much brighter and dustier than our Milky Way galaxy. Their dusty coats light up in infrared wavelengths.

"It's hard to find the most energetic galaxies if you don't know where to look," Eisenhardt said. "We're going to look everywhere."

WISE will also provide a complete inventory of dusty planet-forming discs around nearby stars, and find colliding galaxies that emit more light, specifically infrared light, than any other galaxies in the universe. WISE is expected to produce more than 1 million images, from which hundreds of millions of space objects will be catalogued.

WISE may be able to confirm the existence of dark energy, which scientists believe comprises more than 70 percent of the universe, and which Albert Einstein postulated in 1917. Einstein later believed that to be a serious blunder, but it looks like he was correct, Wright said.

The cryogenic instrument will be built by the Space Dynamics Laboratory in Logan, Utah, and the spacecraft will be built by Ball Aerospace and Technologies Corporation in Boulder, Colo. Science operations and data processing will take place at the JPL/Caltech Infrared Processing and Analysis Center.

Wright; John Mather, chief scientist for the James Webb Space Telescope, and NASA's Cosmic Background Explorer (COBE) team were jointly awarded the 2006 Gruber Cosmology Prize in August for their research confirming that our universe was born in a hot Big Bang; Mather also shared the 2006 Nobel Prize in Physics. The instruments aboard COBE, launched in 1989, looked back over 13 billion years to the early universe. COBE showed that the young universe was hot, dense and almost uniform; that it contained weak fluctuations or lumps that grew into the galaxies and stars we see today; that these fluctuations were the consequence of a hot Big Bang, and that the universe is filled with diffuse radiation from previously unknown galaxies.

For more information about the WISE mission, visit http://wise.ssl.berkeley.edu/

Source: University of California - Los Angeles

Related stories:

A Star That Bursts, Blinks and Disappears
(PhysOrg.com) -- "Twinkle, twinkle little star" goes the nursery rhyme. Now, astronomers are reporting on a strange case where one of the littlest of stars "twinkled" with gamma rays, X-rays, and light -- and then vanished.
The hibernating stellar magnet: First optically active magnetar-candidate discovered
Astronomers have discovered a most bizarre celestial object that emitted 40 visible-light flashes before disappearing again. It is most likely to be a missing link in the family of neutron stars, the first case of an object with an amazingly powerful magnetic field that showed some brief, strong visible-light activity.
Swift Catches Farthest Ever Gamma-Ray Burst
(PhysOrg.com) -- NASA's Swift satellite has found the most distant gamma-ray burst ever detected. The blast, designated GRB 080913, arose from an exploding star 12.8 billion light-years away.
James Webb Telescope components pass tests
You might think that shaking and freezing a state-of-the-art, meticulously crafted machine is a bad idea. But when it comes to firing telescopes and their instruments into the frigid cold of space, the more you test your hardware, the better.
1843 stellar eruption may be new type of star explosion
Eta Carinae, the galaxy's biggest, brightest and perhaps most studied star after the sun, has been keeping a secret: Its giant outbursts appear to be driven by an entirely new type of stellar explosion that is fainter than a typical supernova and does not destroy the star.
A fine-tooth comb to measure the accelerating universe
Astronomical instruments needed to answer crucial questions, such as the search for Earth-like planets or the way the Universe expands, have come a step closer with the first demonstration at the telescope of a new calibration system for precise spectrographs. The method uses a Nobel Prize-winning technology called a 'laser frequency comb', and is published in this week's issue of Science.
Spitzer Reveals Stellar "Family Tree"
A new image from NASA's Spitzer Space Telescope tells a tale of life and death, and reveals a rich family history. The striking infrared picture shows a colorful cosmic cloud, called W5, studded with multiple generations of blazing stars.
Watching a 'New Star' Make the Universe Dusty
(PhysOrg.com) -- Using ESO's Very Large Telescope Interferometer, and its remarkable acuity, astronomers were able for the first time to witness the appearance of a shell of dusty gas around a star that had just erupted, and follow its evolution for more than 100 days. This provides the astronomers with a new way to estimate the distance of this object and obtain invaluable information on the operating mode of stellar vampires, dense stars that suck material from a companion.

News discussion:

Space & Earth science news

[Home]   [Full version]